100 billion gallons of water, enough to supply all the homes in New England for almost 4 months;

1.5 billion pounds of crops otherwise fed to livestock, enough to feed the state of New Mexico for more than a year; . . .

If everyone went vegetarian just for one day, the U.S. would prevent:

Greenhouse gas emissions equivalent to 1.2 million tons of CO2, as much as produced by all of France;

3 million tons of soil erosion and $70 million in resulting economic damages;

The article has many more numbers and factoids that paint vegetarianism as a green diet. (I'm still not entirely sure what happens to all the cows after we decide to stop eating them. It seems like we'll have to get through a couple generations of uneaten cows with longer-than-normal lifespans before we see the real benefits of the no-burgers-for-the-planet's-sake movement.)